Rigid, hinged-lid packets of cigarettes are currently the most widely marketed, by being easy and practical to use, and by providing good protection for the cigarettes inside.
A rigid, hinged-lid packet of cigarettes normally comprises a soft inner package housed in a rigid outer package. The inner package comprises a sheet of packing material wrapped about a group of cigarettes; and the outer package comprises a cup-shaped container with an open top end, and a cup-shaped lid hinged to the container along a hinge to rotate, with respect to the container, between an open position and a closed position opening and closing the open end respectively. A collar is normally folded and connected to the inside of the container to project partly outwards of the top end of the outer package and engage a corresponding portion of the inner surface of the lid when this is in the closed position.
Packing machines are known to employ a device for producing sheets of packing material from a web having reference marks, which are normally equally spaced along one edge of the web, and serve to synchronize one or more work stations with the throughput speed of the web.
Unfortunately, the reference marks and other similar distinguishing marks on the sheet of packing material are normally made in ink, which, if not applied properly, may contaminate the group of cigarettes about which the sheet is wrapped.